Solar panel and production method therefor

ABSTRACT

A method is provided for producing a solar panel, which is made by building up a solar cell layer on a glass base as a covering glass, having a good performance in sealing the solar panel. A solar panel produce by the method is also provided. The production method of the present invention comprises a step of building up a solar cell layer which consists of a plurality of films on a glass substrate which is used as a covering glass, a step of removing a part of the solar cell layer which is built up on the glass substrate, a step of sealing the solar cell layer by using a face, which is exposed by the removing of the part of the solar cell layer, for adhering a sealing material.

TECHNICAL FIELD

The invention relates to a solar panel and to a production methodtherefor.

BACKGROUND ART

Generally, a solar panel is made by building up a plurality of filmssuch as a clear electrode film, a semiconductor film, and a metalelectrode film on a base material

FIG. 3 shows a production method for a conventional solar panel. A solarpanel 10 is made by adhering a solar panel module 27, which is made bybuilding up a solar cell layer 25 on a thin glass substrate (glasssubstrate 26), to a covering glass which is made of a glass substrate byusing an adhering sheet 14.

A covering sheet (back up sheet for rear face) 21 is adhered to the rearface, to which the solar cell layer 25 is arranged, of the solar panel10 so as to cover the solar panel module 27 by an adhering sheet(adhering sheet having an adhering face in a rear face) 20. Theperiphery of the covering sheet is covered by a sealing material 22 soas to seal the solar cell layer 25.

FIG. 4 shows another production method of a conventional solar panel. Inthis method, a solar cell layer 25 is directly built on an entiresurface of a glass substrate 15 for covering the solar cell layer 25,and is adhered to the covering sheet 21 by the adhering sheet 20. It ispossible to obtain a solar panel having a desired dimension by cuttingthe solar panel thus constructed. The above production process has anadvantage in flexibility of design.

However, a periphery of the covering glass 15 and an edge of the solarpanel 25 are aligned approximately on the same line, and according tothis alignment, productivity and quality of the solar panel will bedegraded. That is, as shown in FIG. 5, it is necessary to arrange thesealing material 22 between a bottom face and an upper face of the solarpanel so as to cover the edge of the solar panel and also to closelycontact the covering glass 15 with the sealing material 22. According tothe above necessities, the production process for the solar panelbecomes too complex. Because the sealing material 22 is arranged tocover a part of the face of the covering glass 15, qualities such asappearance and amount of accepting light tend to be degraded. Becausethe sealing material 22 is arranged above the face of the covering glass15 and a projecting portion 22 c is formed by the covering glass 15,dust and contaminants tend to adhere and deposit on the covering glass15.

DISCLOSURE OF THE INVENTION

The present invention has been made in view of the above problems andseeks to provide a method for producing a solar panel, which is made bybuilding up a solar cell layer on a glass substrate as a covering glass,having a good performance in sealing the solar cell layer, and also toprovide a solar panel made by the method.

One aspect of the present invention is a production method for the solarpanel comprising a step of building up a solar cell layer which consistsof a plurality of films, a step of removing a part of the solar celllayer and a step of sealing the solar cell layer using a surface of thesolar cell layer, which is exposed by the removing step, as a face foradhering.

According to the above production process, the solar cell layer can besealed by adhering the sealing material to the glass substrate using thesurface of the solar cell layer which is exposed by the removing step.That is, it is possible to ensure a sufficient area for adhering thesealing material, and therefore, it is possible to seal the solar celllayer by using the area for adhering. The sealing material is arrangedonly in a bottom side of the glass substrate so as to seal the solarcell panel but is not necessary to arrange the sealing material in theupper side of the glass substrate. Therefore degrading of the quality ofthe solar panel, for instance an appearance, a reduction in quantity oflight accepted by the solar panel, due to the sealing material which isadhered to the upper face of the glass substrate, and attaching anddepositing of particles, are prevented.

In the step of removing a part of the solar cell layer, it is alsopossible to remove the entirety of the solar cell layer so as to exposea part of the surface of the glass substrate.

According to the face of the glass substrate thus exposed, it ispossible to adhere the sealing material by using the face of the glasssubstrate, which has a good adhesion, so as to ensure sealingperformance.

It is possible for the solar cell layer to comprise, in order from theglass substrate, an alkali barrier film, clear electrode film,semiconductor film and metal film, and the alkali barrier film isexposed by removing any of the films.

In this adhering, because the alkali barrier film which has a goodadhesion is used as the adhering face, it is possible to ensure thesealing performance of the sealing material.

A further aspect of the present invention is that a solar panelcomprises a solar cell layer which consists of a plurality of filmswhich are built on a glass substrate for covering, and any of theplurality of films are removed so as to adhere a sealing material forsealing the solar cell layer by using a face which is exposed by theremoval.

According to the face of the glass substrate thus exposed, it ispossible to adhere the sealing material by using the face of the grasssubstrate, which has a good adhesion, so as to ensure a sealingperformance.

It is possible for the above solar panel to expose a surface of theglass substrate by removing entire of said solar cell layer.

It is also available for the solar cell layer to comprise, in order fromthe glass substrate, an alkali barrier film, clear electrode film,semiconductor film and metal film, and the alkali barrier film isexposed by removing any of the films and is used as an adhering face toadhere the sealing material so as to seal the solar cell layer.

According to the solar panel and the production method of the presentinvention, it is possible to ensure sealing performance of the solarcell layer by using a surface, which is exposed by removing a part ofthe solar cell layer, as an adhering face for the sealing material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1D are schematic views of an embodiment of the productionmethod of the present invention.

FIGS. 2A, 2B and 2C are schematic views of embodiments of the solarpanel made by the production method of the present invention, whereinFIG. 2A shows a construction of a solar panel which solar cell layer issealed by the sealing material using the surface of the glass substratewhich is exposed by removing the solar cell layer, FIG. 2B shows aconstruction of a solar panel which solar cell layer is sealed by thesearing material using the face of the alkali barrier film which isexposed by removing any of the films, FIG. 2C shows a construction of asolar panel which solar cell layer is sealed by two layers of sealingmaterial by using the surface of the glass substrate which is exposed byremoving any of films.

FIG. 3 is a schematic view of a solar panel which is made by aconventional production process.

FIG. 4 is a schematic view of a conventional production process of asolar panel.

FIG. 5 is a schematic view of the solar panel made by the conventionalproduction process.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the production method and the solar panelmade by the production method of the present invention will be explainedin reference with the figures.

FIGS. 1A to 1D show schematic views of a process of the productionmethod of a solar panel of the present invention. In this embodiment,the production method consists of the following processes.

First process: As shown in FIG. 1A, building up a solar cell layer 25which comprises a plurality of films.

Second process: As shown in FIG. 1B, removing a part of the solar celllayer 25.

Third process: As shown in FIG. 1C, adhering a covering sheet 21 to thesolar cell layer 25, which is built up on the glass substrate 15 forcovering the face of the solar cell layer 25, by using an adhering sheet20.

Fourth process. As shown in FIG. 1D, sealing the solar cell layer 25 bya sealing material 22 in order not to degrade a generating performanceof the solar cell layer 25 due to absorption of moisture.

The solar cell layer 25 comprises, for instance, in order from the glasssubstrate 15, an alkali barrier film, a clear electrode film, asemiconductor film, and a metal film, and has a layered construction.

A method of a mechanical process and a method of a chemical process areavailable for removing any of the films of the solar cell layer 25. Thismethod of removing the films using a mechanical process are, forinstance, a method of grinding the films by a grinding wheel, a methodof blasting, for instance a sand blasting, and a method of irradiating alaser beam, for instance, an excimer laser etc.

In this embodiment, a film in a periphery of the solar cell layer 25 isremoved by using any of the above mechanical and chemical methods. If itis necessary to divide the entire solar cell layer 25 into severalpieces, the periphery of the films to be removed are removed aftercutting the glass substrate 15 for dividing the solar cell layer 25 intopieces of preferred dimensions. A preferable amount of an area to beremoved in the solar cell layer 25 is sufficient for closely contactinga sealing material 22 to the solar cell layer 25.

The solar cell layer 25 is sealed by using the face, which is exposed bythe above removing process, as an adhering face, and covering theperipheries of the solar cell layer 25, adhering sheet 20, and coveringsheet 21. In this embodiment, an area for adhering the sealing material22 to the glass substrate 15 is arranged by removing the solar celllayer 25; therefore, the sealing process is simplified. That is, by theprocess of this embodiment, because the solar panel can be sealed bysupplying the sealing material 22 to one side (bottom side) of the glasssubstrate 15, a process of sealing can be completed more easily than theconventional process for sealing. The sealing material 22 is arranged inthe bottom side of the glass substrate 15 so as to seal the solar cellpanel and is not arranged in the upper side of the glass substrate 15.Therefore degrading of the quality of the solar panel, in appearance,and reducing the quantity of light accepted by the solar panel, due tothe adhered sealing materials, and adhering and depositing of particlesare prevented.

FIGS. 2A to 2C show embodiments of a solar panel made by the process ofthe present invention. In these embodiments, the solar cell layer 25 hasa build up construction which comprises, in order from the glasssubstrate 15, an alkali barrier film 17, a clear electrode film 11, asemiconductor film 12, and a metal film 13.

In the solar panel in FIG. 2A, a glass surface of the glass substrate 15is exposed by the above exposing of the films, and the solar cell layer25 is sealed by the sealing material 22 by using the exposed glass facefor a face for adhering the sealing material 22 to the glass substrate15.

In this embodiment, the glass surface which has a good adhesiveness isused as the adhering face to the sealing material 22 for sealing thesolar cell layer 25. Therefore, the solar cell layer 25 can be certainlysealed by using the glass face of the glass substrate 15 which has agood adhesion. In the process of exposing, it is possible to ensureexposing the glass face by grinding not only the entirety of solar celllayer 25, but also a part of the glass substrate 15, to a predetermineddepth.

In the solar panel of FIG. 2B, the alkali barrier film 17 is exposed bythe exposing process, and the alkali barrier film 17 is adhered to thesealing material 22 so as to seal the other films, such as the clearelectrode film 11, the semiconductor film 12, and the metal film 17.

In this embodiment, the solar cell layer 25 is also certainly sealed bythe sealing material 22 by using the alkali barrier film 17, having asufficient adhering performance, as an adhering face. The alkali barrierfilm 17, such as one of SiO₂, is arranged to prevent diffusion of analkali, which is contained in the glass substrate 15, to the solar celllayer 25, and also to prevent degradation of the performance of thesolar cell layer 25. Therefore the alkali barrier film 17 can beomitted, if the glass substrate 15 does not contain very much alkalinecomponent.

In the solar panel of FIG. 2C, a first sealing material 22 a is arrangedwhich is adhered to the glass face which is exposed by the aboveexposing process using the glass face as an adhering face, and furtherto the first sealing material 22 a, a second sealing material 22 b isarranged for covering the first sealing material 22 a. That is, thesolar cell layer 25 is sealed by the first and second sealing materials22 a and 22 b. A material having a good sealing performance due to lowmoisture permeability, such as materials in a series of butyl rubber andisobutylene-isoprene, is preferable for the first sealing material. Amaterial having a good adhesion performance and a weatherproofperformance, such as types of silicone rubber (general silicone sealantfor construction), is preferable for the second sealing material 22 b.

The solar cell layer 25 of the embodiments in FIGS. 2A to 2C ensuressealing performances due to the multiple sealing.

The solar panel made by the process of the above embodiments ensuressealing performance by using the face which is exposed by removing thesolar cell layer for the adhering face to adhere to the sealingmaterial. The exposed face is used for the adhering face for adhering tothe sealing material; therefore, it is preferable to make the exposedface to be smooth so as to increase an adhering performance by theprocess for removing the solar cell layer. According to the exposed facethus smoothed, it is possible to increase an adhesiveness of thecovering sheet 21 and the sealing material 22. In the above processesfor removing the solar cell layer and increasing the smoothness of theexposed face, a process for increasing the smoothness of the exposedface can be performed by a means other than a means for removing thesolar cell layer. For further increasing the adhering performance, it ispreferable to coat the exposed face with primer materials in order toadd further smoothness and adhesiveness to the exposed face.

1. A production method for a solar panel comprising: a step of buildingup a solar cell layer which consists of a plurality of films on a glasssubstrate which is used as a covering glass; a step of removing a partof said plurality of films which are built up on said glass substrate;and a step of sealing said solar cell layer by using a face, which isexposed by said removing of said part of said solar cell layer, foradhering a sealing material.
 2. A production method for a solar panelaccording to claim 1, wherein a part of the face of said glass substrateis exposed by removing the entirety of said solar cell layer.
 3. Aproduction method for a solar panel according to claim 1, wherein saidsolar cell layer comprising, in order from the glass substrate, analkali barrier film, a clear electrode film, a semiconductor film, and ametal film, and said alkali barrier film is exposed by removing any ofsaid films.
 4. A production method for a solar panel according to claim1, wherein, said sealing material comprising a first sealing materialand a second sealing material.
 5. A production method for a solar panelaccording to claim 2, wherein said sealing material comprising a firstsealing material and a second sealing material.
 6. A production methodfor a solar panel according to claim 3, wherein said sealing materialcomprising a first sealing material and a second sealing material.
 7. Aproduction method for a solar panel according to claim 4, wherein saidfirst sealing material has high sealing performance and said secondsealing material has high adhesion performance and a weatherproofperformance.
 8. A production method for a solar panel according to claim5, wherein said first sealing material has a high sealing performanceand said second sealing material has a high adhesion performance and aweatherproof performance.
 9. A production method for a solar panelaccording to claim 6, wherein said first sealing material has a highsealing performance and said second sealing material has a high adhesionperformance and a weatherproof performance.
 10. A solar panel comprisinga solar cell layer which consists of a plurality of films which arebuilt on a glass substrate, wherein any of said plurality of films areremoved so as to adhere a sealing material for sealing said solar celllayer by using a face which is exposed by said removing.
 11. A solarpanel according to claim 10, wherein said sealing material is adhered tothe exposed face by using said glass substrate as an adhering face so asto seal said solar cell layer.
 12. A solar panel according to claim 10,wherein said solar cell layer comprising, in order from the glasssubstrate, an alkali barrier film, a clear electrode film, asemiconductor film, and a metal film, and said alkali barrier film isexposed by removing any of said films and is used as the adhering facefor sealing any of said films.
 13. A production method for a solar panelaccording to claim 10, wherein said sealing material comprises a firstsealing material and a second sealing material.
 14. A production methodfor a solar panel according to claim 11, wherein said sealing materialcomprises a first sealing material and a second sealing material.
 15. Aproduction method for a solar panel according to claim 12, wherein saidsealing material comprises a first sealing material and a second sealingmaterial.
 16. A production method for a solar panel according to claim13, wherein, said first sealing material has a high sealing performanceand said second sealing material has an adhesion performance and aweatherproof performance.
 17. A production method for a solar panelaccording to claim 14, wherein, said first sealing material has a highsealing performance and said second sealing material has an adhesionperformance and a weatherproof performance.
 18. A production method fora solar panel according to claim 15, wherein, said first sealingmaterial has a high sealing performance and said second sealing materialhas an adhesion performance and a weatherproof performance.